For autonomous driving systems and driver-assistance systems to safely pilot vehicles, it may be beneficial for the systems to have access to a high accuracy map of the roadways which the vehicle is navigating. The high accuracy map may provide the autonomous driving system with an indication of what objects are present nearby, such as ahead on a roadway and hidden around a turn. Such a high accuracy map may include significantly more information than a typical navigational map. For instance, a high accuracy map may indicate the presence of traffic lights at an intersection, where roadway signs, lane markings, curbs, traffic islands, etc., are located. Generation of such a high accuracy map may typically be labor-intensive. For example, a human may manually review and tag objects present in images captured of a roadway environment. While such a manual arrangement may be acceptable for small geographic regions such as for testing purposes, such an arrangement may not be practical for large-scale generation of high accuracy maps, such as nationwide or worldwide.